The U.S. health care system is facing a major challenge of high and growing health care costs. It has been estimated that the country spends $226 billion annually on low-value medical services that provide very little or no patient benefit. Thus, reducing the incidence of such low-value medical care is a major policy priority. Although recent cost containment policies have focused on incentives for provider organizations, little is known about the relationship between provider organizations and overuse. In addition, while many quality measures have been developed to assess underuse in administrative data, few such measures assess overuse. The overall aim of this project is to use novel direct measures of overuse in order to understand provider organizations' role in the delivery of low-value care. The proposed research will involve highly specific measures of low-value services that the principal investigator and collaborators have developed based on published evidence-based lists of low-value services. These measures will be applied to Medicare claims data, which, along with physician group practice data, will be used to test several hypotheses related to the role of provider organizations in low-value care delivery. Statistical analyses will assess pattern of low-value care within organizations (i.e. correlations across different services, persistence of service use over time, cohesion of physician behavior changes) and across organizations (i.e. organizational factors associated with low-value service delivery). This project will be conducted by an MD/PhD graduate student studying the economics of health care policy.